The present invention relates to a wheel bearing assembly for an automotive wheel, and more particularly to a bearing assembly equipped with means for detecting the number of revolutions of a wheel hub to control an automobile by means of an anti-skid braking system (hereinafter abbreviated to ABS).
The ABS is provided to control the braking force according to the number of revolutions of wheel hubs so that the wheels will not lock and thus the automobile will not skid. For this control, an ABS-equipped automobile requires bearing assemblies capable of detecting the number of revolutions of the wheel hubs.
FIG. 8 shows a prior art bearing assembly of this type. A wheel bearing 1 for a wheel has a pulse ring 3 in the form of a gear press-fitted on the outer periphery of an outer member 2 at one end thereof and a solenoid sensor 4 disposed so as to face the outer periphery of the pulse ring 3. Since the pulse ring 3 is made of stainless steel to protect it from rust, it is not only heavy but also its material and manufacturing costs are rather high.